Brian Dunn, the chief executive of America's biggest electronics retailer Best
Buy, has abruptly quit as the company scrambles for a strategy to combat
growing competition from Amazon.

Mr Dunn, who had been at the helm for close to three years, had been criticised for not recognising the scale of the challenge that Best Buy faces from internet retailers such as Amazon, discount chains including Wal-Mart, and from the rise of Apple stores.

Best Buy, which built its success around the creation of huge shops, slumped to its first annual loss in more than two decades in 2011 as customers migrated online. Although Best Buy's online sales are climbing, its large stores have become an increasing financial burden to a company struggling to lift revenue. Sales climbed less than 1pc last year.

"It was time for new leadership to address the challenges that face the company," Best Buy said, claiming Mr Dunn's resignation had been by "mutual agreement". Mike Mikan, a board director, will take over as an interim chief executive.

Last month Best Buy announced plans to close 50 of its "big-box" stores and open more of its smaller outlets that focus on selling smartphones. Wall Street analysts said the move would not be sufficient to revive one of America's best-known retailers.

Mr Dunn, who joined Best Buy as a VCR salesman in 1985, told Bloomberg last month: "I believe I absolutely am the right person to lead the company forward. I'm not really spending a lot of time looking in my rearview mirror."